A highly purified preparation of carnitine octanyl transferase activity has been isolated from beef heart mitochondria. This enzyme also has carnitine palmityl transferase activity. Characterization of the kinetic, chemical and physical properties will continue. An enzyme which decarboxylates alpha-ketoisocaproate (the keto acid of leucine) has been partially purified from the cytosol fraction of rat liver. Purification and characterization of this enzyme will continue. The products of the reaction, cofactor requirements and kinetic characteristics of the purified preparation will be determined. Other studies will focus on the role of carnitine in the carnitine requiring yeast Torulopsis bovina. The acylcarnittne carnitine content of this organism grown in the presence of oxygen and in the absence of oxygen will be determined. Other studies will include a determination of the sideness of the carnitine acetyltransferase and the carnitine octanyl transferase of rat liver microsome (endoplasmic retculum).